#![doc = include_str!("README.md")]
#![forbid(unsafe_code)]

use std::{ffi::OsStr, io::Write};

/// Default initialization
///
/// Sets the main crate log level to `info`, everything else to `warn` by default.
/// Allows overriding from `{main}_LOG` and `RUST_LOG`.
///
/// Invoke as:
/// ```
/// femtofemme::init(env!("CARGO_CRATE_NAME"));
/// ```
pub fn init(main: &str) {
    init_custom(
        &[
            format!("{}_LOG", main).as_str(),
            format!("{}_LOG", main.to_uppercase().replace('-', "_")).as_str(),
            "RUST_LOG",
        ],
        &format!("warn,{}=info", main.to_lowercase()),
    );
}

/// Custom initialization
///
/// Read the filter from the first set environment variable, or fall back to a default.
pub fn init_custom(env: &[impl AsRef<OsStr>], default_filter: &str) {
    env_logger::Builder::new()
        .format(|buf, record| {
            let mut levelcolor = buf.style();
            levelcolor.set_color(match record.level() {
                log::Level::Error => env_logger::fmt::Color::Red,
                log::Level::Warn => env_logger::fmt::Color::Yellow,
                log::Level::Info => env_logger::fmt::Color::Green,
                log::Level::Debug => env_logger::fmt::Color::Blue,
                log::Level::Trace => env_logger::fmt::Color::Magenta,
            });
            writeln!(
                buf,
                "{} {} {}",
                chrono::offset::Local::now().format("%Y-%m-%d %H:%M:%S"),
                levelcolor.value(record.target()),
                record.args(),
            )?;
            #[cfg(feature = "kv")]
            {
                struct Visitor<'a> {
                    buf: &'a mut env_logger::fmt::Formatter,
                }
                impl<'kvs, 'a> log::kv::Visitor<'kvs> for Visitor<'a> {
                    fn visit_pair(
                        &mut self,
                        key: log::kv::Key<'kvs>,
                        val: log::kv::Value<'kvs>,
                    ) -> Result<(), log::kv::Error> {
                        let mut bold = self.buf.style();
                        bold.set_bold(true);
                        writeln!(
                            self.buf,
                            "    {} {}",
                            bold.value(key),
                            format!("{:#?}", val).replace('\n', "\n    ")
                        )?;
                        Ok(())
                    }
                }
                let mut visitor = Visitor { buf };
                record.key_values().visit(&mut visitor).unwrap();
            }
            Ok(())
        })
        .parse_filters(
            env.iter()
                .find_map(|e| std::env::var(e).ok())
                .as_deref()
                .unwrap_or(default_filter),
        )
        .init();
}